DMDAAC/AM copolymers as deinkers

Abstract

The instant invention is directed to a method for deinking cellulosic fibrous material impregnated with ink wherein a mixture of said material and water is stirred in the presence of a deinking agent, the improvement wherein the deinking agent is a hydrolyzed copolymer of dimethyldiallyl ammonium chloride and acrylamide.

What is claimed is: 
     
       1. In a method for deinking cellulosic fibrous material impregnated with ink wherein a mixture of said material and water is stirred in the presence of a deinking agent, the improvement wherein said deinking agent is a hydrolyzed copolymer of dimethyldiallyl ammonium chloride and acrylamide, wherein the molecular weight of said copolymer is 2,000,000 to 10,000,000 as determined by gel permeation chromatography, and wherein 0.01 to 0.1%, by weight, of said copolymer is used, based on a dry paper weight. 
     
     
       2. The method of claim 1, wherein said hydrolyzed copolymer also is prepared from up to 5%, by weight, diethyldiallyl ammonium chloride. 
     
     
       3. The method of claim 1, wherein 4 to 5%, by weight, of said acrylamide is hydrolyzed to acrylic acid. 
     
     
       4. The method of claim 1, wherein the weight ratio of acrylamide to dimethyldiallyl ammonium chloride is 75:25 to 25:75. 
     
     
       5. The method of claim 4, wherein the weight ratio of acrylamide to dimethyldiallyl ammonium chloride is 55:45 to 45:55.